PPT: General Design Requirements | Design of Steel Structures - Civil Engineering (CE) PDF Download

 Page 1


Steel Structures 3 
Key Formulas and 
Concepts
A comprehensive guide to essential formulas and 
principles for designing and analyzing steel structures 
in civil engineering.
by Support EduRev
SE
Page 2


Steel Structures 3 
Key Formulas and 
Concepts
A comprehensive guide to essential formulas and 
principles for designing and analyzing steel structures 
in civil engineering.
by Support EduRev
SE
Introduction
Importance
Steel structures form the 
backbone of modern 
infrastructure. They offer 
superior strength-to-weight 
ratios compared to other 
materials.
Applications
From skyscrapers to bridges, 
steel provides versatility. Its 
ductility makes it ideal for 
seismic design.
Key Topics
We'll explore tension 
members, compression 
members, beams, and 
connections. Each 
component requires specific 
calculation methods.
Page 3


Steel Structures 3 
Key Formulas and 
Concepts
A comprehensive guide to essential formulas and 
principles for designing and analyzing steel structures 
in civil engineering.
by Support EduRev
SE
Introduction
Importance
Steel structures form the 
backbone of modern 
infrastructure. They offer 
superior strength-to-weight 
ratios compared to other 
materials.
Applications
From skyscrapers to bridges, 
steel provides versatility. Its 
ductility makes it ideal for 
seismic design.
Key Topics
We'll explore tension 
members, compression 
members, beams, and 
connections. Each 
component requires specific 
calculation methods.
Tension Members
Definition
Structural components subjected to axial tensile 
forces. They resist pulling actions in the structural 
system.
Without Stress Reversal
Slenderness ratio must not exceed 180. This 
prevents excessive deflection under load.
With Stress Reversal
For dynamic loads like wind or earthquakes, 
slenderness ratio limit increases to 350.
Page 4


Steel Structures 3 
Key Formulas and 
Concepts
A comprehensive guide to essential formulas and 
principles for designing and analyzing steel structures 
in civil engineering.
by Support EduRev
SE
Introduction
Importance
Steel structures form the 
backbone of modern 
infrastructure. They offer 
superior strength-to-weight 
ratios compared to other 
materials.
Applications
From skyscrapers to bridges, 
steel provides versatility. Its 
ductility makes it ideal for 
seismic design.
Key Topics
We'll explore tension 
members, compression 
members, beams, and 
connections. Each 
component requires specific 
calculation methods.
Tension Members
Definition
Structural components subjected to axial tensile 
forces. They resist pulling actions in the structural 
system.
Without Stress Reversal
Slenderness ratio must not exceed 180. This 
prevents excessive deflection under load.
With Stress Reversal
For dynamic loads like wind or earthquakes, 
slenderness ratio limit increases to 350.
Net Sectional Area
For Plates
Net area = (b × t) 3 n × d × t
For Single Angles
A_net = A1 + k × A2
Key Variables
b: width, t: thickness, n: holes, d: diameter, k: reduction 
factor
The net sectional area accounts for material removed by holes. For single angles, the reduction factor k is typically 0.7.
Page 5


Steel Structures 3 
Key Formulas and 
Concepts
A comprehensive guide to essential formulas and 
principles for designing and analyzing steel structures 
in civil engineering.
by Support EduRev
SE
Introduction
Importance
Steel structures form the 
backbone of modern 
infrastructure. They offer 
superior strength-to-weight 
ratios compared to other 
materials.
Applications
From skyscrapers to bridges, 
steel provides versatility. Its 
ductility makes it ideal for 
seismic design.
Key Topics
We'll explore tension 
members, compression 
members, beams, and 
connections. Each 
component requires specific 
calculation methods.
Tension Members
Definition
Structural components subjected to axial tensile 
forces. They resist pulling actions in the structural 
system.
Without Stress Reversal
Slenderness ratio must not exceed 180. This 
prevents excessive deflection under load.
With Stress Reversal
For dynamic loads like wind or earthquakes, 
slenderness ratio limit increases to 350.
Net Sectional Area
For Plates
Net area = (b × t) 3 n × d × t
For Single Angles
A_net = A1 + k × A2
Key Variables
b: width, t: thickness, n: holes, d: diameter, k: reduction 
factor
The net sectional area accounts for material removed by holes. For single angles, the reduction factor k is typically 0.7.
Compression Members
Definition
Members subjected to axial compressive forces. These 
include columns and struts in structural systems.
Axial Load Capacity
P = Ã_ac × A, where A is cross-sectional area and 
Ã_ac is permissible compressive stress.
Merchant-Rankine Formula
1/ Ã_ac = 1/ Ã_y + 1/ Ã_cr, where Ã_y is yield stress 
and Ã_cr is critical stress.